Human Thermal Tolerance And Environmental Control Strategies Forhumid And Hot Environments Under Deep Mine With Intelligent Mining

With the depletion of shallow coal mine resources and the increase of mine mining depth year by year,deep shaft heat damage has become an important factor affecting mine safety production.The traditional overall cooling mode consumes huge energy,and with the continuous promotion of intelligent mining technology,the number of mine workers is reduced,so it is more advantageous to use local cooling technology in the workers’ activity area.China’s Coal Mine Safety Regulations stipulate that the maximum working face temperature should not exceed 30℃.And the research of the group and some domestic and foreign experts found that the existing environmental control standards for coal mine working face have exceeded the human thermal tolerance limit.In this paper,the maximum permissible exposure time of human body is studied by combining the predicted heat stress(PHS)model of human body,and the PHS model of hot and humid environment is modified by using theories of heat and mass transfer in porous media,body temperature physiology,and clothing ergonomics,etc.The effects of different environmental temperatures,humidity,and wind speed on the maximum permissible exposure time of human body are studied,and an environmental control strategy that considers the economy and the maximum permissible exposure time of human body is proposed.control strategy considering economy and maximum allowable human exposure time.The main findings are as follows:(1)the predicted heat stress model of human body in humid and hot environment is modified;(2)the maximum permissible human exposure time increases gradually when the air velocity increases from 1 m/s to 4 m/s;the increase of wind speed has a more obvious effect on the increase of maximum permissible human exposure time at lower relative humidity compared with higher relative humidity(>80%);the maximum permissible human exposure The maximum permissible human exposure time decreases with the increase of relative humidity and decreases with the increase of air temperature;among them,air temperature has the most significant effect on the maximum permissible exposure time.(3)Considering the maximum allowable exposure time of human body and the operating cost of the system,the recommended wet bulb temperature range is given for 6-hour and 8-hour working systems with different wind speeds,and the recommended control wind speed for 8-hour working system is 2.5m/s,corresponding to the maximum allowable wet bulb temperature of 26.5℃;the control wind speed for 6-hour working system is 2m/s,corresponding to the maximum allowable wet bulb temperature of 28.1 ℃.This paper is of great significance for further research on the thermal tolerance of human body in the hot and humid environment of mines,and provides theoretical support for the improvement of the thermal environment control standards to ensure safe production in mines.